Diaphragm valve



March 16,1937; f i PtKQSAU'NDl-:RS 2,074,240

DIPHRAGM VALVE Filled Aug 22, 19.55 s sheets-sheet 1 Patented Mar. r 16v', 19.37vv

l emunio nmnnAcM AvALvn Philip Keith Saunders, Wolverhampton, England. assignor to Saunders Inventions Limited Johannesburg, Union of South Africa Application August 22, 1935,

sei-nino. yanni In Great Britain August 23, 1934 s claims.. (ci. asi-ao).

Diaphragm valves have numerous advantages over the plug-cock type of valve, but one advantage that the latter has over the former-in ordinary conditions is that it can be quickly moved from the fully-open to the fully-closed position, whereas normally a number of turns of van actuating spindle is necessary for effecting the corresponding operation of a diaphragm valve. Furthermore,when a plug-cock is not provided with any 10 stop thel actuating handle can be moved beyond the fully-closed position without any damage beingdone; b ut excessive pressure applied -to the actuating means of a diaphragm valve, for closi ing it, will cause damage to the valve, particularly in the case of a small diaphragm valve.

' The vpresent inventionparticularly relates to "streamline diaphragm valvesthat is, to the kind where the body has a substantially straightthrough passage intersected by a shallow barrier 20 extending across the passage and havinga concave face which forms a seating for the diaphragm, the base wall of the passage curving up smoothly to the concave face on each side of the barrier. l r l The main object of the present invention is to provide improvements in' diaphragm valves by which the `above-mentioned drawbacks of diaphragm valves will be remedied.` 1

A further object of the invention is to provide a quick-acting actuating mechanism which can be embodied in a diaphragm valve of standard construction with substantially no alteration to the valve except for the replacement `of partsv of .the actuating mechanism.

Broadly speaking, the invention comprises a toggle, cam `or equivalent actuating mechanism for a diaphragm valve whereby the diaphragm can be quickly moved from the fully-open to the 4fully-closed position, for example, by turning an 40 actuating member through less than one complete revolution, and held in the closed position. Preferably the mechanism` is such as to be irreversible bythe fluid pressure lacting on the diaphragm, when the latter is closed. For example, a'toggle slightly overset against a stop is irreversible by the iluid pressure.

According to a further feature of the invention,

an eccentric or other cam of a quick-acting pattern, for operating the diaphragm, has a portion of its operative contour such that the diaphragm will be held in the fully-closed position for different positions of the cam. n

According to a further feature of the present invention, the diphragm ofl a diaphragm valve is operated by a toggle, quick-actingcam or equivalent means. providig a varying .leverage and adapted to hold the diaphragm in the fully-closed position. i -The invention further consists in a diaphragm valve'v where the diaphragm is actuated in the closing direction against spring pressure by a quick-acting cam rotatable about an axis transverse to that ofthe diaphragm.

' According to a further feature of the invention, the actuating mechanism of a diaphragm valve includes a bush supporting a rotatable cam which yengages a stern movable axially of the bush.

A further feature of the invention includes'a I quick-acting rotatable cam connected with an` t axiallyi-movabie stem,.for opening andclosing the valve, so as positively tol-.move the stem in both directions. According to a further feature of the invention,

the diaphragm of a diaphragm valve is actuated through -a pluralityof easy-faced cam or equivalent devices arranged in series, i. e., acting one through another.

' According to a still further feature of the vinvention, the diaphragm of a diaphragm valve is actuated through an intermediate member formed on opposite faces, with easy cams co-actlng, respectively, with equivalent' cams on the valve body, or on a cover therefor, and on an actuator for the diaphragm; the cams having flats adapted for holding the actuator with the' diaphragmin the closed position. Y

In the accompanying drawings:-

; Figure 11s a perspective ,exploded" view of one form of actuating mechanism, according to the invention,'suitable for a, relatively small valve:

l Figure 2 is a part-sectional elevation of a valve fitted with the actuating mechanism of Figure 1,

the valve being shown closed;

Figure 3 `is a substantially valve when open;

Figure 4 is a plan of the intermediate member; Figures 5 and 6 arediagrams illustrating the position of the intermediate member relative to the cover and actuator when thev valve ls closed and open, respectively; '4 y .Figure 'I is a part-sectionalperspective view, with the handle and cam shown detached, of another form of actuating mechanism according to the invention, which is suitable for a larger valve; s p

Figures 8 and 9 are fragmentary sectional views showing the cam when closed, respectively; p.

Figure 10 is an enlarged 4sectional elevation similarA view of the the valve is open and showing a modified form of cam and tappet. for use instead of that of Figures 7 and 9; and

Figure 11 is a cross-section taken on the line XI--XI of Figure 10, this figure indicating also an alternative method of clamping the cam in a selected position.

In the construction of Figures 1 to 6, which is eminently suitable for relatively small .stream line diaphragm valves and with which the overall dimensions of the valve are not materially increased, use is made of the intermediate member aforesaid.. 'I'his is an annulus Il disposed within a cylindrical portion of the cover I2 for the valve body I3. On each of its opposite faces are provided two diametrically-opposite rising ,cams with smooth, inclined surfaces I4, Il and I5, I5. Corresponding diametrically-opposite inclined cam surfaces I6 and I1 are provided on the adjacent surfaces of an actuator I8 for the diaphragm and of the far end of the cover, respectively. The extremities of all the cam surfaces are flattened, as shown at I9. The intermediate member is, in fact, like a wavy ring with a central axial flange 20. The cams on one sur- :ace are in series-with those on the opposite surace.

In the open position of thel valve (Figure 3) the inclined cam surfaces' I5, I4, on the inter. mediate member rest against the corresponding inclinations I6, I1 on the actuator and the cover, respectively, as shown in Figure 5, when the actuator is as near that end of the cover as possible. On twisting the intermediate memberas by ,means of a handle 2l fast on the shank portion 20 of the memberit is itself forced axially away from the adjacent 'end of the cover Y and at the same time the actuator is forced axially away from the intermediatefmember, as the various inclined surfaces ride up one another- 40 the actuator being slidably guided and held against rotation in the cover'by means of the lugs 22 sliding' in the grooves 23 of the cover. When the parts have been fully expandedin this manner the appropriate cam flats II are in 'engagement and' the actuator is thus held'in this position, in which the diaphragm is fully closed, as shown by Figures 2 and 5.

The axial distance between the flats Il of the cams onthe opposite faces of the intermediate member must be accurately arranged to ensure that the diaphragm will be fully closed in the above conditions. Fine adjustment can be effected by tightening the nuts or screws 2l by which the cover clamps the diaphragm 2l against the valve body.

Conveniently, the shank`2l of the' intermediate member is' bored freely to receive a spindle 2l pinned at 21 or otherwise connected to the adjacent face of the actuator.` A compression a0 spring 28 may be interposedjbetween a head 2l on this spindle and an inturned flange Il of the intermediate member, so that at all times the actuator will be1 biased towardsv the intermediate member.

-- o5 The inclinations of the cam surfaces are sufnciently "easy" to'allow of operation in this man- 'ner from the fully-open to the fully-closed position when the intermediate member is turned through approximately one quarter revolution. If the latter be turned further than the fullclosing position, as it can'be, no damage will b e done to the diaphragm but the valve will just be re-operated towards the open'position. 'Closing can be effected by rotation of the intermediate member in either direction. The fully-closed position of the diaphragm is nmintained, in this construction, for a handle movement of over 30- in point of fact, for a movement of about For larger sizes of "streamline" diaphragm valves an operating -mechanism with even less 6 friction is, in ordinary conditions, desirable; and in the constructions of Figures 'I to 11 and particularly in that of Figures 7 to 9 the diaphragm 25a (clamped against the body Ila which is substantially similar to the body I3 of the valve oi' l0 Figures 1 to 3) is forced in the closing direction by means of an actuator IIa formied with arms 3| which serve for the support of the i'iexible portion of the diaphragm when the valve is closed. 'I'he arms are arranged to co-act with 16 grooves 32 'formed in the cover I2a of the valve, the lower edges (not visible in the drawings) of the walls defining the grooves constituting supports 'for the ilexible portion of the diaphragm when this is fully opened. In the present in- 20 stance use is made of a bush Il entered through the opening at the upper end of the cover Ila of the valve. The bush-carries a flange u by which its inward movement is limited and it is vexternally screw-threaded at the lower end Il to 25 take into a nut 36 placed in the interior of the cover. During the screwing of the bush into the nut the latter can be prevented from rotation if formed with an arm 31 engaging one of the grooves 32 of the cover. At its lower end the 30 bush is provided with a short inturned flange II which supports the lower end of a compression spring 22a. It may. in addition, provide a stop to limit the outward movement of the actuator. as shown in Figure 1. 35

As thus described the cover and actuator may be identical with those of a known form of "streamline diaphragm valve, though the bush. which is usually rotatable, Is replaced by the present bush which is held in the cover against 40 movement.

In the present instance the bush is continued well up beyond the top of the cover, and longitudial slots 3l diametrically opposite one another are formed in its open end which is thus forked. 45 Interposedinthcseslotsisacamllintheformof an eccentricdisc, this being pivotallysupported from the bush by means of a cross pin 4|.

- The bush may be formed with bosses l2 to receive this. The lower edge of the cam engages a tappet 50 43 which is conveniently provided with ears Il disposed one on each side of the cam. The

vtapilet is connected by a thrust rod Il with the actuator Ila, this preferably'being hinged to the rod as shown at '21s. The compression spring 55 28a bears against the underside of the tappeti Extending from the periphery of the cam is an actuating handle Ila.

The contour ofthecam is such that when the handle is turned from the fully-open towards the o0 A fully-closed position. the first portion' of the movement eifects a relatively rapid closing of the diaphragm, when the resistance is relatively light, but the next portion of the movement effects aslower movement of the diaphragm as it 65 is being-forced against the resistance into its fully-closed position. During the final movement of the handle a concentric portion 4I of the cam.y co-acts with thetappet so that the' wiiibeheldcloledssaimtanyopeningnressure 'lov applied by the mud ontrcuea by the valve. 'In this way it is posibleby turning the handle throughadistanceistgresterthanllo'tomove '4 the 'diaphragmrapidln and with esse. fromthe` fully-open to the position. or vice 7&5l

so This second'kindof isslidably-mounted upon .is of non-circular section, taking. into corre--Y sponding holes in' the bushes 5I',.iilqriwhich areH 'f rotatively journalled in holes 'provided in theearsf I mentto the leftV (Figurel gaged by, the wing valve) is to' be heldin sonic intermediateposil- VVV`tion' lthe nut 50 can be screwed down th ,SL 'After any clearance.

` :fand theadjacent surface' beenftak'en' up on axialmovement .orfit gialla, the further rotation of .the Vmit the'bushl' axially clainp the cam Ila'against the-surface ofthe'adA -this movement closes the valve tothefextent'of about 92%;- As the remaining onethirdfotfthe other end of? the cross pinhas ascrew receiving the winglnut 5 6.

' fluid Pressure foi` mineor pit4 cages. Forexample'when thefcage 1.5 nearing the ,hmmm .the OPeIStQl" i me. say. .throush-tyvo-thirds ci its-travel' uc3m y,

versa, even inthe case of a very large valve. v l Y i The tappetmay be adjustablymounted upon the thrust rod,l as shown at 41, and in this case adjustment of the valve can be effected by means of thetappet'. l

In some cases it may position, 4and a Vconvenient method of arranging for this consists in using a boltas thepivot pin 4| for the cam, the bolt'carrying on itsfree endV a Wing nut 4B which can be tightened to clamp the cam in a setposition betweenV the two jaws of the forked end of the bush. y

Only alight compressionv sp `n need beused for returning the 'compressor -to the fully-open position when the cam has been appropriately turned, asthe opening movement of the diaphragm is assisted by the pressure. ofV the uid :controlled by the fvalve. Obviously if the pressure of this is relativelylow a'stronger spring maybe used.

In some cases as that marked28a in Figures l'Ito 9 disadvan- 4tageous, and in the modification'indicatedV by Figures 10 and llnosuch spring Here the ears 44a of. the tappet "43a, which have a.'v screw-threaded connection' at IT- with a thrust; rod 45a pinned at Z'lato the compressor Ilia,v

are formed withV uinwardly-extending pins 19 which engage peripheral anges ililformedon the tappet-'ispositive-1-. ly pulled open or pushed 'dQwn' according to the the cam 40a. In this event `direction in whichthe'cam 40a is turned. 'Y

Furthermore, in this modification the. cam theicross p in (la which;v1

52. 'Ihese ears are Vin this Vcase; formed"integrally the cross pin to the right- Illi to jacentear 5l. Inthiswayitcanbejfrl'ctionally eld against' rotation.' '5;' quick-actins'vQIYeIQIEs 7 to 1 1) is-vexy use `cam and means carried by said the use of a return spring siuilziV said passage,

. phragm,

.diaphragm includinga'comp're Vthe idiaphragm, Asaid compressor having ngers nannies-.ine snap f @ne has.-

-suitable-for controlling the in 'the imei"ation" ofxmany.` g;

in on 'direction when nut is tightcootroi 8% ef, the diaphragmmovemen and easily, and held in the closed position.

Y What I claim as" myl invention and desire to v secure by Letters Patent of the United States is 1. Actuating mechanism for adiaphragm valve,

including an axially-movable st em for openingl .and closing the valve, cam, and means a quick-acting rotatable vinterconne ting said cam and stem whereby said stem is vp oi-.itivel`y movable in both directionsv on appropriate operation of said cam, said means including a anged'rrim on the stemengaging opposite sides of sid anged rim, and said anged rim .having a portion removed to allowofA assemsage, a shallow barrier extending partly across said barrier having a concave face which forms a seating vfor a Vdiar'neter of the diathe base Wall .of said vpassage curving up smoothly to the concave means for the ssor 'connected to adapted to pass between those of 'said body, an

` axially-movable stem connected toV the compres- ;sor, and a quick-acting oamassociatedwith said stem -wherebythe diaphragm can bemoved from thefully-Open to the Yfully-closed .position by movement or the cam .through `an-angle of--less than 360, said cam having' itsoperative surface 'shaped so that -the rate ofmovement of the diatphxasm when the -s'peed to closel 'is tu'rnediatv a uniform the diaphragm isa-maximum at thebeginning, when the pressure. ofthe compres- .sniff on the diaphragmis'afminimuxmthe `dia.- ;fphragm then being .partiallysupported by the nsscal'ried bythe body. the; rate of movement -vof.thediaphragrn thereafterv decreasingto-a' min-v Y is nearly 'closed' `when the pair'of outwardLvjextending-fears, an axactuating thediaphragm,

slidablymounted infV one fof, said ears, and fo theffaxialimovement of said E enedonlfsaidlcross' pin,..whereby 'said nut on' be-' saidgcmss pin wm einer axial from the fullyeclosedto the fullyeopenposition, and vice versa, very.. quickly A be desirable for the diaphragm valve to be maintained in a partly-open risixi'g a bony hav-Y ed to. recfvea mit fengaging'the adjend or oneoft said bushes,4 said ,one bush tatingbringing the cage quickly and safely to' d rest. 'Ihus,

face on each'side of the barrier.. spacedfingers carried by. the. b 'ody for Y'supporting the main portion of 4said diaphragm- 'when fully opened, and actuating ,chemie i am ed am i Y. 2o. 2. A diaphragm valve comprisinga diaphragm, a' body with a substantially straight-through pas- 

